Effect of Extraction Time on the Yield, Chemical Composition, and Antibacterial Activity of Hop Essential Oil Against Lactic Acid Bacteria (Lactobacillus brevis and Lactobacillus casei) Beer Spoilage.

Hop essential oil (EO) generates interest for its antioxidant and antimicrobial properties, in addition to the volatile compounds that are responsible for the hop aroma in beer. Thus, the objective of this study was to evaluate the chemical composition, EO yield, and antibacterial activity of hop essential oil from hops of the Chinook variety against lactic acid bacteria (Lactobacillus brevis and Lactobacillus casei) at different times of extraction. EO extraction was performed by hydrodistillation at different times. By analyzing the chemical composition by gas chromatography and mass spectrometry, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined. The major compounds of hop EO were α-humulene, ß-myrcene, and ß-caryophyllene, and the extraction yields were 0.67, 0.78, and 0.85% mass of EO per mass of hops pelletized hops (m/m), for extractions of 90, 180, and 300 min, respectively. The EO obtained in 90 min was efficient against L. casei at 2.5 mg/mL (MIC) and 5.0 mg/mL (MBC), and the 300 min one against L. brevis at 2.5 mg/mL (MIC) and 25 mg/mL (MBC). The antibacterial activity was affected by the chemical makeup of the oil, revealing that the hop EO extracted in 300 min was the most efficient among the other extraction times.

The influence of the environment in the incorporation of copper and cadmium in scraper insects.

In regions with intense agricultural activity, increases in heavy metal concentrations in aquatic environments are common. Among the metals associated with agricultural activities, copper (Cu) and cadmium (Cd) have been found to directly affect aquatic trophic structures due to the ease of incorporation by primary producers and consuming organisms. Aquatic insects are predominantly found in streams, and their presence is determined by environmental characteristics and food availability. In this study, we seek to understand how the incorporation of Cu and Cd by scraper insects relates to their environment and food sources. We collected water, sediment, biofilm and scraper insect samples in streams with different intensities of agricultural activities in the drainage areas. The intensity of agricultural activities in the catchment area positively influenced the Cu and Cd concentrations in organisms and other aquatic compartments. The metals were readily incorporated by the biofilms. Although the functional characteristics are important to understand the functioning of ecosystems, in this study, we found that the physiological characteristics can be determinants in the concentrations of metals in aquatic insects.

Antinociceptive effect and mechanism of supercritical carbon dioxide extract of Aloysia gratissima leaves in mice.

BACKGROUND: A. gratissima is a shrub used in folk medicine as analgesic and sedative. However, studies on its antinociceptive activity are scarce. This research aimed to evaluate the antinociceptive effect of a supercritical carbon dioxide (SCCO2) extract of A. gratissima leaves (EAG) in mice. METHODS: A. gratissima leaves were subjected to extraction with supercritical CO2 (60 °C, 200 bar). The chemical composition of EAG was determined by gas chromatography-mass spectrometry (GC-MS). The antinociceptive profile of the extract (1, 10 and 30 mg/kg, p.o.) was established using acetic acid-induced abdominal contraction tests and formalin-induced paw-licking tests. The open field and rota-rod tests were used to evaluate a possible interference of EAG on mice motor performance. The contribution of the opioid system and adenosine triphosphate (ATP) sensitive K+ channels in the mechanism(s) of EAG action was evaluated by specific receptor blockers. EAG's acute toxicity was investigated using OECD 423 guideline. RESULTS: The GC-MS revealed the presence of sesquiterpenes (guaiol and pinocamphone) in the EAG. Doses of 10 mg/kg and 30 mg/kg significantly reduced the number of abdominal writhes and paw licking time in mice in the formalin test. The EAG did not affect the locomotor activity and motor coordination of the mice. The antinociceptive effect of the EAG was prevented by glibenclamide in the mice formalin test, unlike naloxone pre-treatment. The acute administration of EAG caused no mortality. CONCLUSION: A. gratissima leaves possess antinociceptive effect, mediated by K+ channels sensitive to ATP.

Estudo da atividade metanogênica específica de diferentes lodos anaeróbios / Study of specific methanogenic activity of different anaerobic sludges

RESUMO O estudo da atividade metanogênica específica (AME) constitui uma importante ferramenta para o controle operacional de reatores anaeróbios, pois apresenta parâmetros de monitoramento da eficiência e estabilidade de um reator biológico. Nesse sentido, o presente trabalho visou determinar a AME de lodos provenientes de reatores anaeróbios de fluxo ascendente (UASB - upflow anaerobic slugde blanket) de duas indústrias cervejeiras (lodos A e B), uma de processamento de grãos (lodo C), uma leiteira (lodo D) e uma de processamento de couro (lodo E). Os ensaios foram conduzidos em batelada, em ambiente aclimatado a 35°C, utilizando um equipamento para monitorar a geração de biogás em função do tempo de digestão. Também foi realizada a qualificação do gás metano presente no biogás gerado pelos diferentes lodos. O maior valor de AME obtido e a maior porcentagem do gás metano produzido, para uma concentração de biomassa de 5,0 gSTV.L-1 e 4,0 gDQO.L-1 de glicose, foram para o lodo B: 0,36 gDQO-CH4.gSTV-1.d-1 e 58,9%, respectivamente.

ABSTRACT The study of Specific Methanogenic Activity (SMA) is an important tool for operational control of anaerobic reactors, as it presents parameters to monitor the efficiency and stability of a biological reactor. For this reason, the present article aimed to determine the SMA of sludges from UASB reactors, of two different brewing industries (sludges A and B), a grain processing industry (sludge C), a dairy industry (sludge D), and a leather processing industry (sludge E). Assays were performed in batch, at an acclimatized environment (35°C), using a device equipment to monitor the generation of biogas due to digestion time. Also, the quantity of methane gas was measured in the biogas generated by the different sludges. The best SMA value obtained and the greater percentage of methane gas generated, with a biomass concentration of 5.0 gSTV.L-1, and a glucose concentration of 4.0 gCOD.L-1, were for sludge B, with 0.36 gCOD-CH4.gSTV-1.d-1 and 58.9%, respectively.

Iron and manganese present in underground water promote biochemical, genotoxic, and behavioral alterations in zebrafish (Danio rerio).

Iron (Fe) and manganese (Mn) are metals commonly found at high concentrations in underground water. These metals are essential for the good functioning of living organisms, but high concentrations lead to imbalance, potentiating the appearance of pathologies. This study aimed to evaluate the effect of exposure to naturally occurring metals in groundwater, using zebrafish (Danio rerio) as an experimental model. Thus, zebrafish were exposed to Fe (0.8 and 1.3 mg/L), Mn (0.2 and 0.4 mg/L), and groundwater collected from deep tube wells with Fe and Mn (Fe 0.8/Mn 0.2 mg/L and Fe 1.3/Mn 0.4 mg/L) for 30 days. Bioaccumulation of these metals has been demonstrated in the livers and muscles of zebrafish. Acetylcholinesterase activity changed only in zebrafish muscles in all groups. Sulfhydryl levels changed mainly in the group Mn 0.4. SOD/CAT ratio decreased in the groups Fe 0.8 and 1.3, Mn 0.4, and Fe 0.8/Mn 0.4. An increase in the frequency of micronucleus in all groups was shown as a consequence of these changes. Behavioral parameters (time and distance traveled, mean speed, turn angle, latency, and number of crossings between compartments) have also changed, mainly in the groups Fe 1.3, Mn 0.4, and Fe 1.3/Mn 0.4. Therefore, long-term exposure to Fe and Mn, even at not so high concentrations, may cause biochemical, genotoxic, and behavioral changes in zebrafish.

Protective role of jaboticaba Plinia peruviana peel extract in copper-induced cytotoxicity in Allium cepa.

Jaboticaba Plinia peruviana (Poir.) Govaerts is a Brazilian berry that presents high levels of polyphenols, which may play a key role in preventing cytotoxic and genotoxic effects of harmful agents. Although copper is an essential micronutrient that plays an important role in organisms, high copper concentrations may trigger toxicity to animals and plants. Here, we investigated whether Plinia peruviana hydroalcoholic extract prevents copper-induced cytotoxicity in Allium cepa root cells. Five different anthocyanins and phenolic compounds were identified in Plinia peruviana extract. Importantly, the exposure to 1.53 mg/L copper for 24 h impaired mitotic index, as well as increased mitosis disturbances and triggered DNA damage. Pre-incubation with Plinia peruviana extract (0.25 g/L and 0.75 g/L) for 3 h prevented copper-induced changes in the mitotic index and reduced the number of abnormal cells. In conclusion, we suggest that Plinia peruviana peel extract has protective effects against cellular and genetic disturbances induced by copper.

Extraction, chemical characterization and antioxidant activity of Litchi chinensis Sonn. and Avena sativa L. seeds extracts obtained from pressurized n-butane.

The extraction of litchi (Litchi chinensis Sonn.) and oat (Avena sativa L.) seeds were investigated using n-butane as pressurized solvent by evaluating the effect of pressure in the range of 7-100 bar and temperature from 25 to 70 °C on the extract yield and chemical composition together with the antioxidant activity of the extracts obtained. It was experimentally observed extraction yields for both seeds up to ~3.5 wt%, with a total phenolic content around 126.4 mg GAE/100 g of extract, and an antioxidant activity up to 78.36%. Oat seeds extract presented higher values of these parameters evaluated compared to litchi extract. Based on the results found, it seems that n-butane may be a promising solvent to conventional extraction methods, as mild operating conditions and eco-friendly solvent can be used to provide good results without any residues in the final product.